arXiv subjects

C. Guthmann

Publications and source records attributed to C. Guthmann.

3 recordsLinked to original sources

arXiv2006

Determination of the interactions in confined macroscopic Wigner islands: theory and experiments

Macroscopic Wigner islands present an interesting complementary approach to explore the properties of two-dimensional confined particles systems. In this work, we characterize theoretically and experimentally the interaction between their basic components, viz., conducting spheres lying on the bottom electrode of a plane condenser. We show that the interaction energy can be approximately described by a decaying exponential as well as by a modified Bessel function of the second kind. In particular, this implies that the interactions in this system, whose characteristics are easily controllable, are the same as those between vortices in type-II superconductors.

cond-mat.mes-hall↗

arXiv2003

Dispersive charge transport along the surface of an insulating layer observed by Electrostatic Force Microscopy

We report the observation in the direct space of the transport of a few thousand charges submitted to a tunable electric field along the surface of a silicon oxide layer. Charges are both deposited and observed using the same Electrostatic Force Microscope. During the time range accessible to our measurements (i.e. $t=1\sim1000\un{s}$), the transport of electrons is mediated by traps in the oxide. We measure the mobility of electrons in the "surface" states of the silicon oxide layer and show the dispersive nature of their motion. It is also demonstrated that the saturation of deep oxide traps strongly enhance the transport of electrons under lateral electric field.

cond-mat↗

arXiv2001

Macroscopic 2D Wigner islands

In this paper we present new versatile "2D macroscopic Wigner islands" useful to investigate the various behaviors observed in mesoscopic confined systems. Our "Wigner islands" consist of electrostatically-interacting charged balls with millimetric size. We have experimentally determined the ground configurations for systems of N particles (N=1-30) confined in a parabolic potential and checked the influence of the confinement and interacting potentials. The results obtained are compared with the published numerical results.

cond-mat.mes-hall↗